What is Polymer Clay?

Polymer clay is polyvinyl chloride or PVC, similar to the plastic used in plumbing today. When it is baked properly, polymer clay chemically changes to form a solid mass that doesn’t shrink. You can heat it again, which will soften it slightly without melting. A word of caution... if you get it too hot, it will darken and can give off noxious fumes and possibly catch fire. Use an oven thermometer to check your oven’s temperature.

Polymer clay is not a true clay. It is called clay because of it’s moldable properties, not because it is traditional clay. The word Polymer is added to differentiate. Polymer clay can be molded to imitate a variety of materials, making it very versatile.

True clay is basically finely ground sand particles mixed with water. When it is heated the water evaporates and the particles melt. It needs to be heated much hotter than a household oven or toaster oven can heat. Usually a kiln is needed to reach the temperatures needed.

Polymer means many units of a molecule. When you add the word Polymer to Clay, you are meaning tiny grains of plastic or polyvinyl chlorides (PVC). Instead of water, it is mixed with plasticizers and colorants. If you leave a piece of polymer clay on a piece of paper, the greasy spot left behind is the plasticizers being leached out.

Polymer clay is manufactured by many companies and comes in wonderful colors. You can also mix your own colors or paint your piece before or after baking. (Check out the Poly Clay Play Rainbow of Color System!)

After you mold your polymer clay, you can use a household oven, toaster oven or convection oven to heat it to the temperature required for the brand of clay you are using. The temperature is based on the type of plasticizer used in that particular brand. While heating, the grains of plastic are growing and sticking together. As the piece gets hotter, the fused piece hardens permanently.